The present invention relates generally to the field of the production of oxides of lead, such as litharge and red lead. In particular, the present invention concerns an apparatus and method adapted for the continuous production of these oxides of lead.
Litharge (lead monoxide) is supplied in industrial quantities for use in the pigment industry and in the leaded glass industry. Litharge is produced by oxidation of particulate lead into lead monoxide. Presently, there are two methods employed in the production of litharge. The first method uses a rake furnace to oxidize lead in a batch or continuous process. The second method is a continuous production process which employs a horizontal drying kiln in which lead is tumbled while being oxidized.
Red lead production is typically in a batch process using a rake furnace, for instance. Typically, litharge is maintained in an atmosphere containing oxygen within the furnace for a sufficient amount of time necessary to convert the litharge to red lead.
A typical furnace used in the production of litharge and red lead includes a fossil fuel burner to raise the temperature of the particulate material to the desired reaction temperature. In the furnaces of the prior art, the atmosphere inside the furnace is continuously evacuated into a bag house, which filters out the particulate lead contained therein for environmental reasons.